Electric filter device or system



Feb. 3, 1931. .1. J. PROSKAUER ETAL. 1,791,377

ELECTRIC FILTER DEVICE OR SYSTEM Filed Feb; 20, 1929 Juli/V J Way/raw?ATTORN EY Patented Feb. 3, 1931 UNITED STATES PATENT OFFICE J ULIEN J.PROSKAUER AND HAROLD SHEVERS, OF NEW YORK, N. Y.

ELECTRIC FILTER DEVICE OB SYSTEM Application filed February 20, 1929.Serial No. 341,437.

tutes a single unit which may be connected with radio receivers now inuse without requiring any change in the receiver and wh1ch may beinstalled by one unskilled in the art of radio.

A further object of the invention is the provision of a filter devicewhich may plugged into the wall socket of an electric 2O lighting systemand to which the lead cable from the radio receiver may be connected byinserting the plug thereon into the socket with which the device isprovided, thus requiring no instruments and no possibility of error wheninstalling.

A still further object of the invention is to provide an electric filterwhich includes a pair of radio frequency choke coils arranged in thepower line and a pair of con densers respectively connected to the coilswith a common ground leading from the condensers.

With these and other objects in view, the invention resides in certainnovel construction and combination and arrangement of parts, theessential features of which are hereinafter fully described, areparticularly pointed out in the appended claim, andare illustrated inthe accompanying drawing,

in which Figure 1 is a perspective view of our improved filter in use.

Figure 2 is a perspective view of the several connected parts removedfrom their housing.

Figure 3 is a diagrammatic view of the filter.

Referring to the drawing by reference characters, the numeral 10designates our improved electric filter in its entirety which includes acan shaped receptacle 11 having a removable cover '12 closing theopen'top of the same. Fixed to the underside of the cover is an electricplug receiving socket 13 which opens through the'top" of the cover for apurpose to be presently explained. The cover isalso provided with anopening 14 for the passage of'certain wires hereinafter explained.

Contained within the receptacle 11 are a .pair of radio frequency coilsA and A which are Wound upon cardboard cores or frames 14, theconvolutions of the coils being held to the cores by tapes 15 suitablytied together as shown in Figure 2 of the drawing. The as outer ends ofthe coils A and A are connected by wires B and 'B' respectively whichconnect with the respective terminals of the socket 13. Also connectedto the outer ends of the coils are wires C'and C which have connectionswith condensers D and D respectively. The two condensers are tapedtogether as at 16 into a single unit while a common ground wire Econnects with the condensers 'and passes out through the opening 14 inthe cover 12. It will be noted that the two condensers are interposedbetween the two choke coils, while Wires F and F connect with the'innerends of the respec tive coils A and A and are housed in a single cord Gwhich passes out through the open-v ing 14, the free end of the wirebeing connected toan attachment plug H. r

' To operatively connect the filter device 10 with a radio receiver I asshown in Figure 1 of the drawings, the plug H is inserted in anelectric'socket- J while the plug K provided on the lead L from theradio receiver I is inserted into the socket 1 3. The ground wire E isattached to any convenient ground such as a water pipe or the like andthe device is now set for operation. In practice, the electric currentfrom the source of supply first passes through the coils A and A wiichact to filter the sound or electrical noise frequencies which may bepresent therein, and which electrical noise frequencies are taken outwhen passing through the condensers by reason of the fact that thenatural condenser capacity absorbs the same and which passes to theground through the wire E.

If desired, the container 11 may be filled with pitch or the like tomaintain the several parts in a set position and the cover 12 sealedthereon. This will also prevent tampering with the parts by thoseunskilled in the art as the device is capable of long life ifundisturbed.

Although, we have described the filter device for use in connection witha radio receiver, the same may also be used with other electricalhousehold appliances, such as electric refrigerators, vacuum cleaners,oil burners and any other noise interfering apparatus as it may be thatthe noises present in a radio receiving set are not from the linefeeding the receiver, but from some household appliance. It might alsobe found practical for eliminating generator noises where direct currentis being converted into alternating current for use with alternatingcurrent operated radio receiving sets.

While we have described what we deem to be the most desirable embodimentof our invention, it is obvious that many of the details may be variedwithout in any way departing from the spirit of our invention and wetherefore do not limit ourselves to the exact details of constructionherein set forth nor to anything less than the whole of our inventionlimited only by the appended claim.

What is claimed as new is 2- In an electric filter device foreliminating extraneous oscillations from a radio apparatus and adaptedto be inserted in the circuit connecting said radio apparatus to a mainpower supply circuit, the combination with the said power supply circuitof a pluralityof rectangularly shaped choke coils, each of said coilscomprising a plurality of rectangular turns and rectangular stiffeningmembers, means for connecting one end of each of said choke coils tosaid power supply circuit, a pair of rectangular condensers connected inseries relationship to the other ends of said choke coils, means forbinding said condensers together to form a compact unitary structure,means comprising a cylindrical container provided with an opening andadapted to receive and protect said choke coils and said condensers,

.means carried by a part of said container.

for establishing a connection from said radio apparatus to the commonconnection be signatures.

JULIEN J. PROSKAUER. HAROLD SHEVERS.

